Acyloxy silanes



Patented Apr. 7, 1953 UNITED STATES "ACYLOXY SILANES John B. Rust,East-Hanover, and Homer van TENT OFFICE BeurenYJoy,Montclair, N. J.,assignors, by direct and mesne assignments, of one-half to MontclairResearch Corporation, Montclair, N. J., a corporation of New Jersey, andone-half to Ellis Foster Company, a corporation of New Jersey N Drawing.Application March'27, 1947, serial N0. 737,714

e oiaims. 1

This invention relates'to organo silicon derivatives and particularly toacyloxy silanesgandto processes of making the same, as wellastocompositions and methods of utilizing such derivatives.

It is known that when an alkyl magnesium vhalideis allowed to react withsilicon'tetrachlobe made either by the two step process of first formingthe Grignard reagent and reacting it with the desired silicon,derivativaoriby'the one step processdescribed in application Serial No.509,017, filed November 3, .1943, by Rust and MacKenzie, entitledOrgano-Silicon Derivatives and Process of Making Same. in which. thesilicon derivative such as silicon halideis reacted with ahalo-hydrocarbon in thepresencfe of metallic magnesium.

Among the objects of thepresent invention is the production ofderivatives of these silicon-01s regardless of the methods usedin theproduction of the latter.

Other objects of this invention include the production of stabl1organo-silicon derivatives having a wide varietyof uses in'the arts,such as in the plastics, paint, textile fields and the like. I

still further objects .and advantages of the present invention willappearfrom the-more detailed description set forthbelow, it beingunderstood that this more detailed description is given by way ofillustration and explanation only, and not by way of limitation, sincevarious changes therein may be made by those skilled in the artwithoutdeparting from the scope and spirit of the present invention.

In accordance with this invention, ithasbeen found that the silicon-01s,either as suchpor in dehydrated or partially polymerized condition,

can be acylated, as by conversion intoesters,

which are quite stable at room temperatures under ordinary conditions"but which'rnay be converted intopolymeric substances as bytheapplication of heat or catalysts, particularly acid or basicsubstances, or by a-combination of such methods. These polymericmaterials have high with this invention, the -esters'will be referred toas'the most significant.

The-esters may be formed in a number of dif- I ierent ways asillustrated inthe examples given or low degrees of complexity dependingupon the number of organic radicals such as alkyl groups, andv the sizeof the organic radicals such as alkyl groups, attached to the siliconatom. To illustrate the acylates produced in accordance hereinafter.These esters'maybe produced in the pure state or they can be'madepartially polymeric esters. In the pure state they may take theconfiguration given in the following formula in which'R. isa hydrocarbonradical having-at least 8 carbon atoms, R is-a hydrocarbon radical, andn is not greater than 3. #Where a single substituent hydrocarbongroup isattached to the silicon the formula will be Esterified polymersyproducedfrom such acyloxy derivatives may have the configuration in whichformulas'R and R1 may beit'he same or different organic substituents,particularly aliphatic and carbocyclic such as alkyl, unsaturatedaliphatic, aryl, aralkyl, or cycloaryl groups including methyl, ethyl,propyl, isopropyl, 'butyl,

isobutyl, amyl, hexyl, hep'tyl, *octyl, vinyl, allyl',

butenyl, 'cyclohexyl, propargyl, 'phenyl, tolyl, xenyl, and substitutedaliphatic and carbocyclic groups such as chlorpropyl and chlorphenyl.

In some cases, the esters, such asthe acetates, cure orpolymerize by theelimination of acid anhydride, such as acetic anhydride,

Thus alkyl 'acyloxy silanes, aryl acyloxy silanes, and relatedderivatives having substituent groups as set forth above maybeproducedin which compounds the acyl group isderivedirom an aliphatic oraromaticcarboxylic acid which may be a polybasicacid. 'Thecompoundscontaining hydrocarbon radicals attached to the silicon where thereareatileast Scarbon atoms including both aliphatic-and aromatic or carbo"cyclic'are particularly valuable because the pres- 3 pounds like octylacyloxy silanes, octyl acetoxy silanes, etc.

The following examples illustrate the process of making the siliconderivatives of the present invention and the products derivabletherefrom. In those examples, all proportions are in parts by weight.

Example 1.-A solution of ethyl magnesium bromide in ether was formedfrom 4.86 parts of magnesium, 86.4 parts of ethyl ether and 2 parts ofethyl bromide. This solution was added dropwise to 26.1 parts of silicontetrachloride in 35 parts of ether. When the exothermic reaction hadsubsided, the solution was boiled for 1 hour, then poured onto crackedice. The ether solution was washed with water until neutral, then driedover anhydrous sodium sulfate. 47 parts of acetic anhydride were thenadded and the ether distilled 01f. The temperature was taken to 100 C.,and held for several hours. During this time the temperature rosesomewhat higher and some acetic acid distilled over. The acetates soformed were stable at 100 C., but on pouring a film and baking at 120C., a clear, hard lacquer coating was obtained in a short time.

Example 2.-A solution of butyl magnesium bromide in ethyl ether was madeusing 4.85 parts of magnesium, 86.4 parts of ether, and 30 parts ofn-butyl bromide. The solution was added dropwise to 30 parts of silicontetrachloride in 36 parts of ethyl ether. When all reaction was over thesolution was poured onto cracked ice, washed until neutral with waterand dried over anhydrous sodium sulfate. parts of acetic anhydride wereadded and the ether distilled off. The temperature was taken to 100 C.for 2 /2 hours. The product of a viscous liquid, having the approximatecomposition of A film of this material was poured on a glass plate andbaked at 100 C. It became hard and tough in a short time, aceticanhydride being eliminated during baking as could be detected by theodor. A portion of the butyl silicyl acetate was dissolved in xylene toform a 5% solution. This solution was used to coat steel wool. Afterdrying the wool was exposed to humid, summer shop condi tions for 2months without signs of corrosion developing.

Besides using anhydrides to form the esters, they may be formed in otherways, as by using acid chlorides.

Example 3.--A solution of butyl magnesium bromide in ethyl ether wasmade from 4.86 parts of magnesium, 86.4 parts of ethyl ether and partsof n-butyl bromide. The solution was added dropwise to 28.3 parts ofsilicon tetrachloride in 36 parts of ether. When the reaction was overthe material was poured on crushed ice, washed until neutral with water,then dried over anhydrous sodium sulfate. parts of xylene were added andthe ether distilled 01f. To 21 parts of this xylene solution containing5 parts of butyl silicols, there was added 11 parts stearoyl chloride.The mixture was heated at 100 C. for 4 hours. Hydrochloric acid wasevolved during the reaction. When cool, the butyl silicyl stearatemixture tended to crystallize out of the xylene.

This latter material may advantageously be used at a water-repellent fortextiles.

Example 4.- A solution of butyl magnesium bromide in ethyl ether wasmade from 4.86 parts of magnesium, 86.4 parts of ethyl ether and 30 partn-butyl bromide. This solution was added dropwise to 31 parts of silicontetrachloride in 36 parts of ethyl ether. When the reaction was over,the mixture was poured on crushed ice, washed with Water and dried overanhydrous sodium sulfate. 50 parts of xylene were added and the etherdistilled off. 23.5 parts of the resulting solution containing 5 partsof butyl silicols and 5 parts of maleic anhydride were heated underreflux condenser for 2 hours. The xylene was then distilled off. Asample of the butyl silicyl maleate, which was an extremely viscousliquid, was poured onto a glass plate and baked at 140 C. A hard filmresulted. To the remainder of the maleate, 1.9 parts of diethyleneglycol were added and heating at 160 C. continued. A hard resinousmaterial was obtained.

Example 5.--15.6 parts of the xylene solution of butyl silicolsdescribed in Example 4 and containing 3.33 parts of butyl silicolshaving the approximate composition of (C4Il9)1.1Si(OH)2.9 were mixedwith 4 parts of acetyl chloride and a heated under a reflux condenserfor 3 hours.

Hydrochloric acid was evolved copiously at first and then more slowly. Asolution of polymeric acetate resulted which was completed stable oninspection from time to time during a two months period. No depositcould be detected in the container. A film from the solution baked uphard and glossy at C. in a short time.

Example 6.36 parts of ethyl ether, 2 parts by volume of n-amylbromideand 3 parts of metallic magnesium were mixed and 0.5 part by volume ofmethyl iodide added. After a catalytic amount of the Grignard reagenthad been formed, a mixture of 19 parts of n-amyl bromide and 21 parts ofsilicon tetrachloride were run in at a rate sufficient to keep thereaction mixture warm. 18 parts additional ethyl ether were added andthe mixture refluxed for 1 hour. 43 parts of hexane solvent were addedand the mixture poured on crushed ice, washed and dried. 15.5 parts ofbetachloropropionyl chloride were added and the mixture refluxed for 5hours. I-Iyrochloric acid was evolved during the reaction and a smallamount of brown solid separated from the solution. The solution wasdecanted and diluted with hexane to give a solution of the amylsilicyl-beta-chloropropionate. A film of the material hardened veryslowly on baking at -150" C.

Example 7.Ethyl butane orthosiliconate (butyl triethoxy silane)(C4H9Si(OC2H5)3) 27.5 parts were mixed with 18.5 parts of phthalicanhydride. The mixture was heated at C. for 5 hours during which time areaction occurred to form a product having the probable formula Onwashing the above with sodium hydroxide solution and neutralizing thewash water no precipitate was obtained. This indicated that a completereaction had occurred.

The above material may be used advantageously as a plasticizer forvarious resinous and plastic materials.

Example 8.-11 parts of metallic magnesium and 108 parts of ethyl etherwere mixed and a trace of methyl iodide added to form some methylmagnesium iodide. 51 parts of silicon tetrachloride and 64 parts ofmethyl iodide were mixed and added to the magnesium and ether at such arate that the ether continued to boil. The mixture was then heated for 1hour at boiling. The material was poured onto crushed ice, washed withwater and dried. A solution of (CH3)1.5Si(OH)2.5 was obtained. This Wasdiluted with dioxan and 1 mole of phthalic anhydride added for each m ofmethyl silicol. The solution was refluxed for 4 hours. A small. amountofsolidre ned undissolved. A film. Was poured 01. a plate and gave onbaking at 129? C. a white, amorphous mass.

Many times it is desirable o carry entit esterificationreaction in thepresence of a tertiary aminewhich serves to remove the hydrogen chloridewhen acid chlorides areemployed. Example 9.--A methyl amyl silicol: wasmade by adding "a mixture of 1 mole methyl iodide, 1 mole amyl bromideand 2 moles silicon tetrachloride to metallic magnesium in ethyl ether.The solution was heated for 1 hour, then poured onto crushed ice, washedand dried. One mole of t is mixed alkyl silicol was mixed with 1 mole ofpyridine and 1 mole of benzoyl chloride added- The pyridine served toremove the hydrogen ch oride rapidly from the reaction. The mixture washeated for two hours at boiling. It was filtere free of pyridinehydrochloride and diluted with ethyl acetate to give a solution ofmethyl amyl hydroxy-silicyl benzoate.

When applied to cotton from a solvent and baked the product of the aboveexample gave an excellent water-repellent effect.

Example 10.-1 gram mole of butyl triethoxy silane and 1 gram mole ofbenzoyl chloride and 1 gram mole of pyridine were mixed and heatedtogether at 150 C. for hours. A reaction prodnot was produced having thprobable formula CsHcSi (OCaHa) 2 (OOC.C6H5) Emample 11.--1 gram mole ofbutyl triethoxy silane and 3 gram moles of acetic anhydride were reactedby being heated together at 150 C. for 5 hours. A reaction product wasproduced h v the probable formula C4H9Si(OOC.CI-I3)3.

Example 12.-1 gram mole of octyl triethoxy silane and 3 gram moles ofacetic anhydride were heated together at 150? C. for 5 hours. A reactionproduct was produced having the probable formula CaHmSi(OOC.CH3) 3.

Example 13.-1 gram mole of octyl triethoxy silane and 1 gram mole ofphthalic anhydride were heated together at 150 C. for 5 hours. Areaction product was produced having the probable formula In preparingthe esters, the proportions of esterifying agent to silicon-o1 may vary.Small ratios of esterifying agent to silicon-o1 results in only a smallnumber of hydroxyls being esterified. Desirably an excess of esterifyingagent is used to assure esterification of all of the hydroxy groups.

While pyridine has been referred to above to illustrate the tertiaryamines, other examples are quinoline, alpha picoline, dimethyl benzylamine, dimethyl aniline, trimethyl-, triethyl-, etc. amine, ethylmorpholine.

As the hydrocarbon substituents in the formulas given above, there maybe present alkyl, aryl, olefinyl, alkenyl, alkynyl, arenyl, arynyl,alicyclic, cycloaromatic, aralkyl, derivatives as u trated by methyl,ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, vinyl, allyl, butenyl,the radicals from acetylene, methyl acetylene, propyl acetylene,cyclohexyl, benzyl, phenyl, tolyl, xenyl, chlorphenyl, styryl, andradicals from such derivatives as phenyl acetylene, etc.

The silicon derivatives of the present invention may be used in manydifferent ways. They ay be used as. lacquers. and! adhesives, eitheralone or in admixture. with othercornpletely reacted or potentiallyreactive resins. Such resins include natural resins. such as rosin, 9 mshellac, etc., as well as synthetic resins including urea aldehyde.resins, phenol. aldehyde resins, melamine resins, aniline aldehyderesins, acetone formaldehyde resins, alkyd resins, cumarone resins,polymerized vinyl derivatives and vinyl resins, polymerized acrylicderivatives including the esters of acrylic and methacrylic acids, etc.;also as intermediates for resins and plastics; as, or in, bakinglacquers, etc.

The silicon derivatives of the present invention as illustrated abovemay be used as textile finishing compositions either alone or insolution in solvents to produce special effects such as waterproofing,creaseproofing, wrinkleproofing, to improve the drape of cloth, etc.;which compositions may include resins, etc., as set forth above.

They may also be used in making solid silicon plastics. The siliconderivatives either alone 0 in admixture with other additives includingresins as set forth above, may be mixed with various inorganic ororganic fillers and used for hot molding, extruding, casting, etc.Objects having excellent strength and highly resistant to water andorganic solvents may thus be produced. The norganic fillers include bothfibrous and nonfibrous materials such as the clays like bentonite, mica,asbestos, glass, or cellulosic materials such as paper, cotton, woodflour, etc.

The silicon derivatives prepared in accordance with the presentinvention may be used as lubrieating oils or may be used as additives toboth hydrocarbon oils such as lubricating oils and also for inclusionwith vegetable oils, particularly the drying oils such as linseed oil,and China-wood oil, and the semi-drying oils such as soya bean oil,etc., as well as non-drying oils including castor oil, etc. Thus thesilicon derivatives may be blended or cooked with the vegetable oils.They may serve as modifying agents for fatty oils, and be used in dryingoil varnishes. With the lubricating oils, they may serve ashigh-pressure lubricants.

These silicon derivatives may be used in rustp-roofing and corrosionresisting coatings either alone or in solvents or vehicles, with orwithout additions or inclusions of resins, oils, etc., as set forthabove.

In view of their excellent electrical properties, the derivatives may beused either per se, or as varnishes, etc. in producing coatings orarticles, or coated articles for electrical insulation, etc. Thesesilicon derivatives may also be used in the production of laminatedproducts for bonding together two or more sheets of the same ordifferent organic or inorganic materials.

The silicon derivatives are also utilizable as plasticizers as well asbinders, and their utilization for such purposes may be controlled bythe number of alkyl or aryl or similar substituents introduced into thederivative.

Any of the silicon derivatives referred to herein including thesilicon-01s, their ethers, esters, etc., per se or in dehydrated,polymerized or partially polymerized condition may be used in theproduction of novel types of printing inks as a substitute for the resinor similar solids content thereof, either in whole or in part. In likemanner, they may be used in floor coverings as binders for compositionsused in that art, or as surface or other coatings thereon.

7 Having thus set forth our invention, We claim: UNITED STATESPATENTS 1. An octyl acyloxy silane. Number Name Date An Octyl ace-boxysilane- 2,386,259 Norton Oct. 9, 1945 Octyl Silicon acetate- .r2,386,441 Daudt t. 9, 19 5 5 2,405,988 Barry Aug. 20, 1946 JOHN RUST-2,431,878 McGregor Dec. 2, 1947 Bellstein: Handbuck der OrganischenChemie, REFERENCES CITED 10 4th ed., V01. IV, pages 627-28. Thefollowing references are of record in the Friedel der Chem Page file ofthis patent: (1868)-

1. AN OCTYL ACYLOXY SILANE.